In order to detect surface membrane abnormalities in malignant versus non malignant tumors, we are validating methodology for isolating surface membrane a sheets or ghosts from transplantable rat tumors. O-alkyl lipids in these membranes will be quantitated by photodensitometry. Surface membrane isolation will be carried out by making single cell preparations from various solid tumors. The mechanism leading to increased O-alkyl lipid synthesis in Ehrlich ascites tumor cells may involve reduced long chain fatty alcohol dehydrogenase activity. Thus, fatty alcohol metabolism may be shunted to O-alkyl lipid synthesis. We are, currently, investigating alcohol dehydrogenase activity in normal tissues and in other neoplasms. We have recently provided evidence to show that the O-alkyl lipid bond is formed via the intermediacy of an endiol of acyl dihydroxyacetone-P. In the absence of fatty alcohol this mechanism requires the formation of dihydroxyacetone-P which has exchanged the pro-R hydrogen, and the release of fatty acid which has retained both carboxyl oxygens. These two features of the reaction are under investigation. The latter will be investigated by carrying out the reaction in (180)H2O. Appropriate reaction products will be isolated and characterized by mass spectroscopy.